In order to have Powermenu work in win 8 – 8.1 you must totally disable UAC.

First go into User Accounts in the control panel and select ” Change User Account Control Settings ” and slide the slider all the way down. then press Win+R and type in ” regedit ” without quotes and go to the following key location.>>

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System and double click “EnableLUA” Set it to Zero ( 0 ) and save. Exit regedit and restart the PC.. BANG!!! Powermenu works..